Saturday, 12 April 2014

Neglected or overlooked?

Now's a good time of year to record two of the rarer or more easily overlooked chickweeds. Almost everyone will know Common Chickweed Stellaria media, probably because they have it growing in their garden. Greater Chickweed Stellaria neglecta is somewhat like common chickweed on steroids, and if you find a particularly large chickweed growing in a shady damp place, it's definitely worth a closer look. The key distinguishing characters are that the sepals of S. neglecta are usually larger than 5-6mm, the stamens are normally more than 8 in number and seeds are normally greater than 1.3mm in length. However, you do have to be careful, as S,media can grow large, particularly in fertile sites and may have from 3 to 8 stamens. I spent quite a lot of time looking at large Stellaria specimens last year and there were a few that were just on the boundary between the two species, where I eventually concluded that they were just S. media. If in doubt, take a reference specimen and press it. There's only been one post-2000 record of this species in VC53 (Bourne Woods, R. Jefferson) but I suspect it still probably lurks in some of the other ancient woods, hedgerows and shadier fens, so keep an eye out for it.

Stellaria neglecta 

Lesser Chickweed Stellaria pallida is almost certainly under-recorded. It is small, has a straggly, untidy appearance and is a pale yellowish-green. It's most likely to be found in inhospitable places, such as pavement edges, gravel roads and even mown grassland, where it flowers early in the year and then disappears. The sepals are generally smaller than those of (less than 3mm), there are 1-3 stamens and petals are normally absent. The fruiting pedicels aren't reflexed at all, while those of S. media are curved downwards or flexuose. This species has been recorded from six sites since 2000, but five of those records have been made by me, probably because I see it regularly at a site that I monitor, and therefore notice it elsewhere.

Stellaria pallida showing characteristic growth form

Seed-head of Stellaria pallida

My last species is much more of a long-shot as it has declined significantly nationally and is now listed as Vulnerable in the UK RedList. Mousetail Myosurus minimus is a tiny annual member of the Ranunculuaceae that is characteristic of damp arable ground and cattle-poached areas (such as gateways and drinking troughs) in grazed pasture. However, it can turn up in other bare areas, and for a while there was a substantial colony alongside one of the Peterborough parkways, in an area that was regularly sprayed with herbicide. It hasn't been recorded in VC53 since 1920, but could still be about, as it's appearances are unpredictable and sporadic. The most likely places to find it would probably be cattle-grazed pasture round the Wash or along rivers and washlands, but it could turn up almost anywhere!

Myosurus minimus

Close-up of flowers

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